Crushing roll



1932- c. B. DUCK WORTH 1,885,241

CRUSHING ROLL Filed Oct. 24, 930 2 Sheets-Sheet 1 INVENTOR. Chip/e55. flax/mani Nov. 1, 1932. C B DU'CKWQRTH 1,885,241

CRUSH IIIIII L led Oct. 2 S 0 18 4H :32 A i 2 *tij Patented Nov. 1, 1932 oirAnLns B. 'nuonwon'rn, or MAGNA, UTAH onusnme ROLL 'Applicationifilegl October 24, 1930. Serial No. 490,935,

- 9 This invention relates to grinding or crushing apparatus of the type commonly known as crushing rolls and consisting in general of two" opposing rolls mounted on horizon- 5 tall shafts, between which the material to be crushed or ground-is delivered. The rolls used'ln such apparatus ord1nar1ly consist of a cylindrical shell secured upontwo centers or core members extendingwithin said shell,

provide a roll construction in which the shellis more positively held from turning or slipping on-the core members during the process of grinding.

"-In c rushing rolls for use in dry grinding operations, it has been customary heretofore t'omachine the inner surface of the shell with an outward taper in both'directions from. a plane intermediate the ends thereof .andto use core members having a corresponding taper. In mounting the shell on the core members, the shell was heated to appromr m'atelybOOto 600 F, causing it to expand sufficiently to allow it to be slipped over one of the core members, usually the one secured to the shaft, and the loose corewas then inserted into the shell and pulled into position by bolts extending through .the two core members, until a tight fit was obtained be- 5 tween the tapered faces of the core members and the shell. Upon cooling, the shell contracted sufliciently to provide a tight fit which was relied upon to prevent slipping or turning while in the process of grinding.

, 54 The tapered fit of the core members within the shellserved to lreepthe shell from slippingsidewise off the cores, but in order to prevent turningof the shell on the core memhers, the shell had to be made with an inside @3 diameter somewhat less than the outside diameter of the core members, so that heating to relatively high temperatures, such as mentioned above, was necessary in order to sufiiciently' expand the shell for insertion of the 23.50 core members, and subsequent contraction of invention is.

the shell upon cooling would cause the same to grip the core members tightly. It has been found, however, that even though this shrinking process is carried to the extreme temperatures possible without injnry'to the molecular structure of the steel shells,considerable slipping of the shells on the core members is'enperienced, especially when. the shells are worn thin by continued use and become heated through sufficiently to again expand and'loosenon the core members.

Forcases. where the grindmg process is to ;.be carried .on in the presence'of water, another means of assembly has been used, employing shells and core members substantial ly of the same type as above described. In

such cases the shell is sometimes secured on the core members by driving wooden wedges between the shell and the core members. .In this case the'shell is not required to fit so tightly on the core members andthe shell does not require heating. In the use of these rolls the water causes the wooden wedges to swell and thus tightly grip the shell and the corev members. 1 However, even with this construction the shells frequently slip when they begin to Wear thin.

The purpose of this invention is to overcome the defects of the abovev described means of mounting roll shells on the core members. The invention is applicable to rolls for. use in either dry grinding or wet grinding operations. Y

A particular object of the invent-ion is to minimize the requirementfor shrinkage of the roll shells on the core members in the case of dry grinding apparatus. Furthermore, by thus reducing the temperature to which the shell must be heated for expansion, it is possible to use a harder composition of steel and thus. obtain maximum wearing life, whereas it has heretofore been necessary to use a softer somewhat more pliable steel structure in order to withstand the necessary heat for expansion. 7

A further object of the inventioniis to eliminate the necessity .of machining .a ta? pered fit in the inner faces of the shell, and thus reduce the cost of the shell. T A further object of the invention is to provide a construction in which the shell is positively held from turning or slipping on the core members, regardless of the thickness of the shell, so that it is possible to wear the shells thinner than has heretofore been possible by reason of the tendency to slip or turn after being worn to a certain thickness.

The accompanying drawings illustrate embodiments of my invention and referring thereto:

Fig. 1 is a longitudinal section of a crushing roll particularly adapted for use in dry grinding.

Fig. 2 is a partly sectional view on line 22 in Fig. 1.

Fig. 3 is a section on line 3-3 in Fig. 2.

Fig. 4 is a View similar to Fig. 1 showing a crushing roll adapted for use in wet grinding.

F 5 is a partly sectional View on line 5-5 in Fig. 4.

Fig. 6 is a section on line 66 in Fig. 5.

The form of crushing roll shown in Figs. 1 to 3 comprises a cylindrical shell 1 of suitable diameter and thickness and formed of hard steel or other wear-resisting material. The inner face of said shell is preferably provided with a straight core receiving bore or recess extending inwardly from each end thereof as indicated at 2, and core members 3 and 4 are inserted within the respective recesses at the ends of the shell. At a position intermediate the two ends of the shell, and preferably approximately midway therebetween, the shell is provided with inwardly projecting retaining means extending between the two core members and consisting preferably of an annular flange or shoulder 5 formed integrally thereon between the two bore portions 2. One of the core members such as the member 3 is secured in any suit able manner, as for example by pressing or shrinking, on a shaft 7 extending axially of the shell and this member is preferably provided with a hub portion 8 extending centrally through the loose core member 4 which is formed as an annular ring disposed between the hub portion 8 and the shell 1.

In order to positively prevent turning of the shell on the core members, the shell and the fixed core member 3 are provided with cooperating abutment means positioned to engage one another and prevent such turning or slipping. For this purpose the flange or shoulder 5 may be cut away or recessed at one or more portions of its circumference, as shown at 9, so as to provide two shoulders or abutments at the ends of each such recessed portion, and the abutment means on the fixed core member may consist of one or more lugs 12 formed thereon and projecting therefrom in a direction parallel to the axis of the roll, in position to engage in said recessed portion or portions between the shoulders 11. In the drawings I have shown only one such recess and lug, but it will be understood that any suitable number thereof may be used, spaced at suitable positions.

The core members 3 and 4 may be drawn together so as to clamp the same against the retaining means 5, by means of bolts 13 extending therethrough and provided with nuts 14. One of the core members is preferably provided with recesses 15 for receiving the heads of said bolts while the other core member is preferably provided with recesses 16 for receiving the nuts 14.

in assembling the shell above described, the shaft 7 with the fixed core member 3 secured thereon is placed up on end, the shaft extending for example through a hole in the floor or other suitable supporting means. The shell is then preferably slightly heated but the temperatureto which it must be heated is, in any event, much less than that necessary with the previously used construction above described. For example, the shell may be heated to between 350 to 450 F., and said shell is then placed on the fixed core member 3. It, should be pointed out that the expansion of the shell by heating in this case is only that necessary to permit the shell to be placed over the core members so as to insure a snug therebetween and cause the core to back up the shell against radial strains around its entire periphery andto also prevent access of foreign material therebetween. In this case the fit of the shell on the core does not need to be nearly so tight as heretofore, since the tightness of this fit is not depended upon to prevent turning or slipping of the shell on the core.

In placing the shell on the tight core memher 3, the recess 5 is fitted over the lug or abutment member 12, as shown in Fig. 2. W iile the shell is still hot the loose core member 4 is inserted in position, and the two core members are then pulled in tightly against shoulder 5 by means of bolts 13 and nuts 14. lV hen assembled in this manner, the shell is positively held against turning or slipping by engagement of the abutment member 12 on the core member 3 with one or the other of the shoulders 11 on the shell and is positively held against sidewise movement by engagement of retaining means 5 with the faces of he two core members 3 and 4.

The lug 12 may, if desired, be made of such size as to fit snugly between the shoulders, but I find that the mounting of the shell on the cores is facilitated by making the recess 9 somewhat longer than said lug. as shown. A 'ter mounting the shell on the fixed core member with said recess engaging over said lug, the shell may be turned, while still hot, so as to bring the lug 12 into engagement with the shoulder 11 which will be engaged thereby during operation of the roll, but I find it preferable to leave such clearance as may occur. between said lug and shoulder, to be taken up by slight sliding or turning move- ,1,sss,241

ment of the shell in the actual operation thereof. Such movement ordinarily does not occur until the shell is worn fairly thin, and in any event it takes place very gently, and when the lug finally comes into tight engagement it hol the shell from turning just as effectively as if it were originally designed to make a tight fit.

The form of crushing roll shown in Figs. 4 to 6 is adapted for use in crushing material in the presence of water and is substantially the same as above described with the exception that, instead of shrinking the shell upon the core members, wooden wedges are used for insuring a tight fit therebetween. The

shell 1 may be substantially the same as above described, being provided as before with two straight bores 2' extending inwardly from the ends thereof and an inwardly projecting flange or shoulder 5' between said toward its outer face, as indicated at 18. The

' outside diameter of each core member at the inner face thereof is suflicient to overlap and abut against the flange or shoulder 5 as shown at 19, while the outside diameter there-- of at the outer face is sufliciently smaller than the inside diameter of the shell to provide an annular space permitting wooden wedges 21 to be forcibly driven into position therebetween.

In assembling a roll of this type the parts are preferably first assembled and the wedges placed in position, said wedges being preferably spaced close together around the entire circumference of the annularspace between the shells and the core members, as shown at the right side of Fig. 5. The core members may then be tightly clamped in position of engagement with the flange or shoulder 5, by means of bolts 13 and nuts 14, and the wedges 21 may then be driven in tightly between the core members and the vent radial movement thereof.

shell. Upon wetting of these wedges either by pretreatment with water or by the water present during the crushing operation, the wedges tend to swell and tightly engage both the shell and the core members so as to pre- As in the other form of the invention first described, turning of the shell on the core members is positively prevented by engagement of the lug 12 with one or the other of the shoulders 11, while sidewise movement of the shell is prevented by the tight engagement of the flange or'shoulderrl5 between: the coremembers 3', and 4 I V ,Iclaimi 1. Acrushing'rollcomprising a'cylindrical shell having a straight. core receiving bore extending inwardly from each. endrthereof andinwardly projecting retaining means be tweensaid bores, twocore members disposed ,within the respective bores with their inner ends engaging said retaining means and liavingtheir peripheral-surfaces tapered radially inwardly from their innerto their outer ends, means securing said coremembers together and in engagement with said retaining means, a plurality of wooden wedges fitting tightly between each of said core members and said shell, and cooperating abutment means on said shell and on one of said core members engaging one another to prevent relative turning of said shell on said core members.

2. A crushing roll comprising a hollow cylindrical shell having two cylindrical core receiving bores opening at the respective ends thereof and a substantially centrally disposed inwardly projecting flange member separating said bores, a shaft extendingaxially of 1 said shell, two core members disposed within the respective bores and tightly secured to said shell and serving to clamp said flange portion of said shell therebetween, one of said core members being rigidly secured to said shaft, means securing said core members together, and cooperating abutment means on said flange and on the core member which is secured to the shaft, saidabutment means engaging one another to prevent relative turning of said shell on said core members.

3. A crushing roll comprising a cylindrical shell having a straight core receiving bore extending inwardly from eachendthereof and aninwardlyprojectingannularflangebetween said bores, said flange having its end faces in planes substantially perpendicular to the axis of the roll, two core members extending within the respective bores and having their axially inner ends bearing against said annular flange, means holding said core members together and in engagement with said end faces of said flange, a plurality of woodon wedges fitting tightly between each of said u core members and said shell, and cooperating abutment means on said shell and on one of said core members engaging one another to prevent relative turning of said shell on said core members.

4. A crushing roll comprising a cylindrical shell having a straight core receiving bore extending inwardly from each end thereof and an inwardly projecting annular flange between said bores, said flange having its end faces in planes substantially perpendic ular to the axis of the roll, two core members extending within the respective bores and having their axially inner ends bearing againstsaid annular flange, means holding iii) said core members together and in engagement with said end faces of said flange, said cylindrical shell being provided with a shrunk fit over. and in tight engagement with said core members, and cooperating abutment means on said shell and on one of said core members positioned to engage one another and prevent relative turning of said shell on said core members.

In testimony whereof I have hereunto subscribed my name this 13th day of October,

CHARLES BQ DUCKWORTH. 

